非IoC方式
要獲得上述對象，關鍵Struts 2.0中com.opensymphony.xwork2.ActionContext類。我們可以通過它的靜態方法getContext()獲取當前 Action的上下文對象。 另外，org.apache.struts2.ServletActionContext作爲輔助類（Helper Class），可以幫助您快捷地獲得這幾個對象。
寫個例子測試一下：
請求的頁面是：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head><title>Simple ha page</title></head>
<body>
<h3>hahaha</h3>
<h3>you success,ha</h3>
<br>
request---<%=request.getAttribute("request") %><br>
request2----<%=request.getAttribute("request2") %><br>
session--<%=session.getAttribute("session") %><br>
<br>------
session2--<%=session.getAttribute("session2") %><br>
session3--<%=session.getAttribute("session3") %><br>
session4--<%=session.getAttribute("session4") %><br>
session5--<%=session.getAttribute("session5") %><br>
session6--<%=session.getAttribute("session6") %><br>
</body>
</html>
要獲得上述對象，關鍵Struts 2.0中com.opensymphony.xwork2.ActionContext類。我們可以通過它的靜態方法getContext()獲取當前 Action的上下文對象。 另外，org.apache.struts2.ServletActionContext作爲輔助類（Helper Class），可以幫助您快捷地獲得這幾個對象。
<pre name="code" class="java"><pre name="code" class="java">///我們平時用的，這個很好理解
HttpServletRequest request = ServletActionContext.getRequest ();
HttpServletResponse response=ServletActionContext.getResponse();
HttpSession session=ServletActionContext.getRequest().getSession();
///////通過ActionContext獲得
ActionContext ac = ActionContext.getContext();
//request
HttpServletRequest request2 = (HttpServletRequest)ac.get(ServletActionContext.HTTP_REQUEST);
//response
HttpServletResponse response2 = (HttpServletResponse)ac.get(ServletActionContext.HTTP_RESPONSE);
//session以下是錯誤的，會報異常
java.lang.ClassCastException:
org.apache.struts2.dispatcher.SessionMap cannot be cast to javax.servlet.http.HttpSession
//對於session因爲從ActionContext 獲取的是Map類型，不能強轉化成HttpSession類型，這是ActionContext與ServletActionContext的區別<pre name="code" class="java"><pre name="code" class="java"><pre name="code" class="java">
HttpSession session2=(HttpSession)ac.get(ServletActionContext.SESSION);//錯
HttpSession session3=(HttpSession)ac.getContext().getSession();//同上
HttpSession session4=(HttpSession)ac.get(ActionContext.SESSION);//錯
//session對象被封裝成Map，我們對Map操作就可以
Map session5=ac.getSession();
Map session6=ServletActionContext.getContext().getSession();
session5.put("key5", "value5");
session6.put("key6", "value6");
寫個例子測試一下：
package com.visit.frame.test;
import java.util.Map;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts2.*;
import org.apache.struts2.dispatcher.*;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class HelloAction extends ActionSupport{
private String leaveMessage;
public String execute(){
this.setLeaveMessage("here me");
///我們平時用的，這個很好理解
HttpServletRequest request = ServletActionContext.getRequest ();
// HttpServletResponse response=ServletActionContext.getResponse();
HttpSession session=ServletActionContext.getRequest().getSession();
///////通過ActionContext獲得
ActionContext ac = ActionContext.getContext();
//request
HttpServletRequest request2 = (HttpServletRequest)ac.get(ServletActionContext.HTTP_REQUEST);
//response
// HttpServletResponse response2 = (HttpServletResponse)ac.get(ServletActionContext.HTTP_RESPONSE);
//session
Map session2= (Map) ac.get(ServletActionContext.SESSION);
Map session3=ac.getContext().getSession();//同上
Map session4=(Map) ac.get(ActionContext.SESSION);
//session對象被封裝成Map，我們對Map操作就可以
Map session5=(Map)ac.getSession();
Map session6=ServletActionContext.getContext().getSession();
//
request.setAttribute("request", "request0");
session.setAttribute("session", "session0");
request2.setAttribute("request2", "request2");
session2.put("session2", "session2");
session3.put("session3", "session3");
session4.put("session4", "session4");
session5.put("session5", "session5");
session6.put("session6", "session6");
return SUCCESS;
}
public String getLeaveMessage() {
this.leaveMessage="hhhh";
return leaveMessage;
}
public void setLeaveMessage(String leaveMessage) {
this.leaveMessage = leaveMessage;
}
}
請求的頁面是：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head><title>Simple ha page</title></head>
<body>
<h3>hahaha</h3>
<h3>you success,ha</h3>
<br>
request---<%=request.getAttribute("request") %><br>
request2----<%=request.getAttribute("request2") %><br>
session--<%=session.getAttribute("session") %><br>
<br>------
session2--<%=session.getAttribute("session2") %><br>
session3--<%=session.getAttribute("session3") %><br>
session4--<%=session.getAttribute("session4") %><br>
session5--<%=session.getAttribute("session5") %><br>
session6--<%=session.getAttribute("session6") %><br>
</body>
</html>
